Vaillant Ecotec Plus Boiler

I am having an issue with our boiler not giving constant hot water, also not seeming to get the heating going either, it is showing the message F.25 with 0.5 bars.

How can we fix this??

Thank you.

Stephen

Hello Stephen,

The EcoTEC Plus F.25 error is a safety shut-off function. In this case the flue gas temperature is too high. The Eco tec Plus boilers have a flue gas temperature limiter known as STB. Either this limiter is faulty, sooted up and needs cleaning or replacing. Other causes may be the plug has broken off or the cable harness is faulty.